130
FXUS61 KPBZ 021156
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
756 AM EDT SAT MAY 2 2026
WHAT HAS CHANGED
THE AVIATION DISCUSSION HAS BEEN UPDATED FOR THE 12Z ISSUANCE.
OTHERWISE, NO CHANGES TO THE FORECAST PACKAGE WERE MADE.
KEY MESSAGES
1) AREAS OF FROST PLUS NEAR TO SUB-FREEZING TEMPERATURES
CONTINUES THIS MORNING AND RETURN TONIGHT.
2) WEATHER PATTERN REMAINS ACTIVE THROUGH THE UPCOMING WEEK WHILE
AREA TEMPERATURE GENERALLY REMAINS BELOW SEASONAL AVERAGES.
DISCUSSION
KEY MESSAGE 1...
THOUGH A MIXTURE OF LOW STRATUS AND MID-LEVEL CLOUDS MAY LOCALLY
STUNT COOLING AND/OR FROST FORMATION, THE OVERALL THREAT OF
FROST AND AREAS OF SUB-FREEZING TEMPERATURE CONTINUE THIS
MORNING BEFORE ABATING AFTER SUNRISE.
THE UPPER TROUGH AXIS CROSSES THROUGH THE DAY TODAY, CREATING LOW
PROBABILITY LIGHT RAIN SHOWERS MAINLY IN THE LATE MORNING TO
AFTERNOON PERIOD, BEFORE EXITING EAST. THE COMBINATION OF ONE
LAST REINFORCEMENT OF THE COLDER AIR MASS BEHIND THIS AXIS WITH
CLEARING SKIES AND LIGHT WIND FAVORS ONE MORE NIGHT OF FROST AND
FREEZE CONCERNS. UPGRADE OF THE FREEZE WATCH IN THE WV HIGH
TERRAIN AREA IS LIKELY WITH ADDITIONAL FROST/FREEZE HEADLINES
ISSUED BUT WILL ALLOW CURRENT HEADLINES TO EXPIRE BEFORE
MESSAGING TONIGHT'S RISKS TO VEGETATION.
KEY MESSAGE 2...
HEIGHT RISES AND INCREASINGLY SOUTHWEST FLOW WILL MANAGE TO LIFT
AREA TEMPERATURE CLOSER TO SEASONAL AVERAGES BY MONDAY INTO
TUESDAY; EVEN THEN, ENOUGH WEAK EMBEDDED SHORTWAVE MOVEMENT MAY
PROMOTE LOWER PROBABILITY SHOWER (AND NON-ZERO THUNDERSTORM
PROBABILITY) STARTING EARLY MONDAY MORNING THROUGH TUESDAY
MORNING. ENSEMBLE MODELS AGREE IN THIS BEING JUST A PRECURSOR
TO THE LARGER PATTERN SHIFT BACK TO GREAT LAKES TROUGHING
DEVELOPING BY WEDNESDAY AND LASTING INTO THE END OF THE WORK
WEEK. RESIDENTS ACROSS THE UPPER OHIO RIVER VALLEY CAN EXPECT
MULTIPLE MORE ROUNDS OF RAIN WITH TEMPERATURE TRENDING ABOUT 10
DEGREES BELOW THE DAILY AVERAGES.
THE FINER DETAILS BOTH THE MONDAY/TUESDAY PRE-TROUGH ARRIVAL
PERIOD AND THE LATE TUESDAY/WEDNESDAY TROUGH PERIOD ARE A BIT
MORE VARIED, RESULTING IN VARIANCES IN PRECIPITATION
ONSET/ENDING AS WELL AS COVERAGE AND TOTALS. WHAT CAN BE SAID IS
HIGH CONFIDENCE IN SEVERE/FLOOD THREATS BEING VERY LOW WITH ANY
ACTIVITY THAT DEVELOPS MONDAY INTO TUESDAY MORNING. SEVERE RISKS
RISE SLIGHTLY LATE TUESDAY INTO WEDNESDAY ONLY IN THE SCENARIO
THAT THE COLD FRONT CROSSING BEST MAXIMIZES DESTABILIZATION
ATTEMPTS (HIGHLIGHTED BY 10% PROBABILITY OF ~1000 J/KG SBCAPE).
FLOOD RISKS MAY BE THE MORE NOTABLE ASPECT TO MONITOR GIVEN
FAIRLY SATURATED GROUNDS IN THE REGION AND SCENARIOS THAT SEE
REPETITION OF NARROW HEAVIER BANDS PUSHING 24-48HR TOTALS ABOVE
2", WITH CURRENT PROBABILITIES FAVORED EASTERN OH TO FAR
SOUTHWEST PA FOR SUCH AXIS DEVELOPMENT (CO-LOCATED WITH 10-20%
>2" PROBABILITY).
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
A MIX OF VFR AND MVFR IS ONGOING TO START THE 12Z TAF CYCLE AS
SCATTERED LIGHT SHOWERS MAKE THEIR WAY ACROSS THE NORTHERN HALF
OF THE AREA. WHILE STRATOCU ARE EXPECTED TO FILL IN ACROSS MOST
OF THE AREA THROUGH THE MORNING AND CEILINGS COULD START AT
MVFR, GRADUAL IMPROVEMENT TO VFR IS FORECAST BY LATE MORNING OR
AFTERNOON. LIGHT RAIN SHOWERS HAVE SO FAR BEEN MOSTLY LIMITED
TO AREAS NORTH OF PIT/AGC, BUT ARE EXPECTED TO DEVELOP FARTHER
SOUTH TOWARDS THE I-70 CORRIDOR THIS AFTERNOON WITH A CROSSING
UPPER TROUGH AND STEEPENING LOW-LEVEL LAPSE RATES. DUE TO THE
SCATTERED NATURE OF THESE SHOWERS, CONFIDENCE IN THEM IMPACTING
ANY GIVEN TERMINAL REMAINS TOO LOW TO WARRANT MORE THAN A PROB30
MENTION IN TAFS. IMPACTS WITH THESE SHOWERS SHOULD BE MINIMAL,
PERHAPS BRIEF REDUCTIONS TO MVFR CEILINGS/VISIBILITIES DURING
INSTANCES OF RAIN BUT OTHERWISE REMAINING VFR. SHOWER ACTIVITY
WANES AND VFR PREVAILS WITH CLOUD COVER SCATTERING AFTER 00Z.
WIND WILL GENERALLY RANGE BETWEEN 5-10 KNOTS OUT OF THE WEST
THROUGH MORNING AND EARLY AFTERNOON, THEN SHIFT TO NORTHWESTERLY
DURING LATE AFTERNOON AND EVENING WHILE REMAINING LIGHT.
OUTLOOK...
VFR IS EXPECTED SUNDAY UNDER HIGH PRESSURE. RESTRICTION AND
SHOWER POTENTIAL INCREASE LATE MONDAY INTO TUESDAY AHEAD OF AN
APPROACHING COLD FRONT. A FEW THUNDERSTORMS ARE ALSO POSSIBLE ON
TUESDAY. MORE WIDESPREAD RESTRICTIONS IN SHOWERS ARE LIKELY
TUESDAY NIGHT INTO WEDNESDAY AS A WAVE OF LOW PRESSURE TRACKS
ALONG THE COLD FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ020-021-029-
031-073>078.
FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR PAZ007>009-
013>016-022.
OH...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR OHZ039>041-
048>050-057>059-068-069.
WV...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR WVZ001>004-012-
021-509.
FREEZE WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
WVZ510>514.
DISCUSSION...FRAZIER
AVIATION...CERMAK
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